k54frog

Oh, but that is what makes those mountain drives so much fun! After another 6 weeks and following the advice of keeping the acceleration smooth & under 2500rpm when possible my avg has increased 10% to 20.1mpg. Still haven't gotten her out on the hwy for any length of drive yet and still need to perform the maintenance. (See 9/18/16 post) I use regular (87) fuel here in CA. The higher octane fuel (89&91) is to prevent premature detonation (ping & knock) typically in higher compression and performance engines. As far as Ethanol blend goes... that's a whole different story. Ethanol has less energy per unit volume than straight gasoline which results in less work for a given volume (i.e. per gallon). That means it won't take you as far and leads to fewer miles per gal (or km/L). More significant than all that, however, are the effects of your driving habits.

Had my 2k Legacy Outback Wagon for about three months now. Current ODO=220k. My first 1400 miles have yielded 18.3mpg overall. Mainly short 5-10 mile trips to work, & around town. Nothing Hwy yet to speak of. Needs a bunch of basic maintenance, (oil change, fuel filter, brakes, seeping oil clean-up, lube, AC charge, etc.). Engine is tight & I just can't seem to help myself and love to wind it up to about 5k-6k on acceleration. Seems like the power band starts in earnest at about 2700-3000rpm.